NZ to trial GM onions

New Zealand's Crop and Food Research Institute has received approval from the country's Environmental Risk Management Authority (ERMA) to conduct a contained field trial of genetically modified onions.

The GM onions, which are tolerant to the common herbicide glyphosate, courtesy of Monsanto's proprietary Roundup-Ready technology, will be trialled at a site near Lincoln, in Canterbury province.

The onions were developed by Dr Colin Eadie's research team at Crop and Food in Wellington, in collaboration with US company Seminis Vegetable Seeds, which will have international rights to market seed for any commercial GM cultivars to come out of the trial.

With an annual value of NZ$100 million, onions are New Zealand's fourth-largest horticultural export after wine, kiwi fruit and pears.

Eadie says his team chose onions because weeds are a major problem in the crop, which takes two years to mature. "Onions are a slow-germinating, slow-growing monocot crop, and if broadleaf weeds are not well-controlled, they can swamp the crop," he said.

Broadleaf herbicides are used to control some weeds, but grassy weeds can also be a problem. Eadie said that while onions have some tolerance to broad-spectrum herbicides, too high a dosage can cause misshapen bulbs.

He said his team also chose onions because they have few negatives as as a GM crop. There are no native Allium species in New Zealand, and there is virtually no chance that the GM crop will hybridise with other Allium species like garlic or shallots, which ERMA has specifically nominated as crops that should not be grown on the Lincoln test site.

"Onions are never seen as hedgerow or roadside weeds, and there are no weedy volunteers after the crop, so growers can get the benefits of herbicide reduction without the risk of the crop outcrossing," Eadie said.

Among other conditions imposed by ERMA for the field trial is that the crop must not be allowed to flower and produce pollen. All onions and leaf material from the crop must be destroyed, and ERMA has also restricted the number of onions that can be planted.

The field trial can run for a maximum of 10 years, or five crop generations.

One of the more unusual conditions imposed by ERMA is that the GM lines must contain no more than two inserts of the Roundup Ready gene construct, to reduce the risk of "unanticipated effects".

Eadie said his team had transformed multiple onion cultivars, including long-and short-day responsive types and intermediates, and was now working to select second-generation transformants for the field trial.

He said the field test would be supervised by researchers from other Crown Research Institutes, to avoid any community perception that Crop and Food or its commercial partner, Seminis, may have allowed commercial considerations to influence the results.